Developed a Bearer Token Security Configuration feature for the spring-projects/spring-security repository, focusing on enhancing API security and deployment flexibility. The work introduced a configurable approach to evaluating the access_token query parameter in bearer token authentication, allowing teams to explicitly enable or disable its use. By updating the DefaultBearerTokenResolver and ServerBearerTokenAuthenticationConverter components, the implementation reduced the risk of misconfiguration and potential vulnerabilities. The solution was delivered in Java, leveraging expertise in backend development, OAuth2, and Spring Security. The changes emphasized secure-by-default behavior, traceability through linked commits, and well-scoped modifications without introducing new bugs during the development period.